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26 Cards in this Set
- Front
- Back
the nature of ecology
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ecology is a study of connections in nature
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Which Species Run the World?
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>Multitudes of tiny microbes such as bacteria, protozoa, fungi, and yeast keep us alive
*harmful microbes are the minority *soil bacteria convert nitrogen gas to a usable form for plants *they help produce foods (bread, cheese, yogurt, beer, wine) *90% of all living mass *Helps purify water, provide oxygen, breakdown waste. *Lives beneficially in your body (intestines, nose) |
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Populations
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>A population is a group of interacting individuals of the same species occupying a specific area
*habitat: > Genetic Diversity * In most natural populations individuals vary slightly in their genetic make up |
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The Earth's Life Support Systems
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>The biosphere consists of several physical layers that contain:
*air *water *soil *minerals *life |
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Biosphere
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>Atmosphere
*membrane of air around the planet ^Stratosphere *lower portion of the atmosphere, contains the ozone >Hydrosphere *all the earths water >Lithosphere *earths crust and upper mantle |
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What sustains life on earth?
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>Solar energy, the cycling of matter, and gravity sustain the earth's life.
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What happens to solar energy reaching the Earth?
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>Solar energy flowing through the biosphere warms the atmosphere, evaporates and recycles water, generates winds and supports plant growth.
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Limiting Factors in Aquatic Ecosystems
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>temperature
>sunlight >dissolved oxygen >nutrient availability >salinity: cannot be greater than 6% |
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Producers: Basic source of all food
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>most producers capture sunlight to produce carbohydrates by photosynthesis
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Photosynthesis: A closer look.
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>Chlorophyll molecules in the chloroplasts of plant cels absorb solar energy.
>This initiates a complex series of chemical reactions in which carbon dioxide and water are converted to sugars and oxygen. |
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Consumers: Eating and Recycling to Survive
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>Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains
*herbivores-->primary consumers *carnivores--->secondary consumers and up *omnivores>>both primary and secondary consumers |
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Decomposers and Detrivores
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decomposers: Break down stuff
detrivores: consume waste, but dont break it down very much |
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Aerobic and Anaerobic Respiration: Getting energy for survival
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>Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need.
>This is usually done through aerobic respiration. *the opposite of photosynthesis >Anaerobic respiration or fermentation: *Some decomposers get energy by breaking down glucose (or other organic compounds) in the absence of oxygen. *the end products vary based on the chemical reaction: --methane gas --ethyl alcohol --acetic acid --hydrogen sulfide |
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Two secrets of survival: ENergy Flow and Matter Recycle
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> An ecosystem survives by a combination of energy flow and matter recycling
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Factors That Increase Diversity:
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>Physically Diverse Habitat
>Moderate amounts of disturbance >Small variation in environmental conditions >High diversity at one trophic level increases the diversity at another trophic level >an environment highly modified by life >Middle stages of succession >Evolution |
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Biodiversity Loss and Species Extinction: Remember HIPPO
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>H for Habitat destruction and degradation
>I for Invasive species >P for pollution >P for human population growth >O for over-exploration |
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Why should we care about biodiversity?
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>Biodiversity provides us:
-natural resources (food, water, wood, energy,medicine) -natural services (air and water purification, soil fertility, waste disposal, pest control) -Aesthetic pleasure |
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Energy Flow in ecosystems
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>food chains and webs show how eaters, the eaten, and the decomposed are connected to one another in an ecosystem
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Energy Flow in an Ecosystem: Losing energy in food chains and webs
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>in accordance with the 2nd law of thermodynamics: there is a decrease in the energy efficiency every time energy is reconsumed
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Productivity of Producers: The rate is Crucial:
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>gross primary production (GPP)
-rate at which a producer converts solar energy into other energy |
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Net Primary Production (NPP)
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>NPP= GPR - R
-reat at which producers use photosynthesis to store energy, minus the rate at which they use some of this energy through respiration. |
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Soil: A Renewable Resource
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>Soil is a slowly renewed resource that provides most of the nutrients needed for plant growth and also helps purify water
>MATURE SOILS, or soils that have developed over a long time are arranged in a series of horizontal layers called soil horizons |
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Layers in Mature Soils
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>Infiltration: the downward movement of water through soil
>Leaching: dissolving of minerals and organic matter in upper layers carrying them to lower layers >the soil type determines the degree of infiltration and leaching |
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O and A horizons
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>O horizon: leaf litter layer
> A horizon (topsoil): humus layer - decaying organisms >Importance of these two layers |
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E, B, and C Horizons
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>E Horizon: Leaching (eluviation)
>B Horizon: Subsoil- accumulates iron, aluminum, and organic compounds from above (illuviation) > C Horizon: |
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Some Soil Properties
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>Soils vary in the size of the particles they contain, the amount of space between these particles, and how rapidly water flows through them.
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